VPO catalysts were prepared on oxidized and unoxidized activated carbons differing in initial porous structure. Carbons were oxidized under relatively soft (30% H2O2, 200 degrees C) and hard (50% H2O2, 350 degrees C) conditions. Carbon modification was carried out hydrothermally in a traditional autoclave (HTT) or a microwave reactor (MWT). The synthesis was also carried out under hydrothermal (HTS or MWS) conditions. V2O5 and NH4VO3 were used as precursors. The samples are characterized by diversified porous structure at S-BET = 732-1617 m(2)/g and V-por = 0.44-0.90 cm(3)/g, as well as various degree of VPO crystallinity. Possibility of preparation of the VPO catalysts under ecologically appropriate conditions, i.e. in aqueous solutions, was shown. (C) 2010 Elsevier B. V. All rights reserved.